package org.systemsbiology.jrap;

/**
 * Encodes and decodes to and from Base64 notation.
 *
 * <p>
 * Change Log:
 * </p>
 * <ul>
 *  <li>v1.4 - Added helper methods to read/write files.</li>
 *  <li>v1.3.6 - Fixed OutputStream.flush() so that 'position' is reset.</li>
 *  <li>v1.3.5 - Added flag to turn on and off line breaks. Fixed bug in input stream
 *      where last buffer being read, if not completely full, was not returned.</li>
 *  <li>v1.3.4 - Fixed when "improperly padded stream" error was thrown at the wrong time.</li>
 *  <li>v1.3.3 - Fixed I/O streams which were totally messed up.</li>
 * </ul>
 *
 * <p>
 * I am placing this code in the Public Domain. Do with it as you will.
 * This software comes with no guarantees or warranties but with
 * plenty of well-wishing instead!
 * Please visit <a href="http://iharder.net/xmlizable">http://iharder.net/xmlizable</a>
 * periodically to check for updates or to contribute improvements.
 * </p>
 *
 * @author Robert Harder
 * @author rob@iharder.net
 * @version 1.4
 */
public final class Base64
{
	
	/**
	 * A {@link Base64#InputStream} will read data from another
	 * {@link java.io.InputStream}, given in the constructor,
	 * and encode/decode to/from Base64 notation on the fly.
	 *
	 * @see Base64
	 * @see java.io.FilterInputStream
	 * @since 1.3
	 */
	public static class InputStream
		extends java.io.FilterInputStream
	{
		private boolean encode; // Encoding or decoding
		private int position; // Current position in the buffer
		private byte[] buffer; // Small buffer holding converted data
		private int bufferLength; // Length of buffer (3 or 4)
		private int numSigBytes; // Number of meaningful bytes in the buffer
		private int lineLength;
		private boolean breakLines; // Break lines at less than 80 characters
		
		/**
		 * Constructs a {@link Base64#InputStream} in DECODE mode.
		 *
		 * @param in the {@link java.io.InputStream} from which to read data.
		 * @since 1.3
		 */
		public InputStream(java.io.InputStream in)
		{
			this(in,Base64.DECODE);
		} // end constructor
		
		/**
		 * Constructs a {@link Base64#InputStream} in
		 * either ENCODE or DECODE mode.
		 *
		 * @param in the {@link java.io.InputStream} from which to read data.
		 * @param encode Conversion direction
		 * @see Base64#ENCODE
		 * @see Base64#DECODE
		 * @since 1.3
		 */
		public InputStream(java.io.InputStream in,boolean encode)
		{
			this(in,encode,true);
		} // end constructor
		
		/**
		 * Constructs a {@link Base64#InputStream} in
		 * either ENCODE or DECODE mode.
		 *
		 * @param in the {@link java.io.InputStream} from which to read data.
		 * @param encode Conversion direction
		 * @param breakLines Break lines at less than 80 characters.
		 * @see Base64#ENCODE
		 * @see Base64#DECODE
		 * @since 1.3
		 */
		public InputStream(java.io.InputStream in,boolean encode,
			boolean breakLines)
		{
			super(in);
			this.breakLines = breakLines;
			this.encode = encode;
			bufferLength = encode
				? 4
				: 3;
			buffer = new byte[bufferLength];
			position = -1;
			lineLength = 0;
		} // end constructor
		
		/**
		 * Reads enough of the input stream to convert
		 * to/from Base64 and returns the next byte.
		 *
		 * @return next byte
		 * @since 1.3
		 */
		@Override
		public int read()
			throws java.io.IOException
		{
			// Do we need to get data?
			if (position < 0)
			{
				if (encode)
				{
					byte[] b3 = new byte[3];
					int numBinaryBytes = 0;
					for (int i = 0; i < 3; i++)
					{
						try
						{
							int b = in.read();
							
							// If end of stream, b is -1.
							if (b >= 0)
							{
								b3[i] = (byte) b;
								numBinaryBytes++;
							} // end if: not end of stream
							
						} // end try: read
						catch (java.io.IOException e)
						{
							// Only a problem if we got no data at all.
							if (i == 0)
							{
								throw e;
							}
							
						} // end catch
					} // end for: each needed input byte
					
					if (numBinaryBytes > 0)
					{
						Base64.encode3to4(b3,0,numBinaryBytes,buffer,0);
						position = 0;
						numSigBytes = 4;
					} // end if: got data
					else
					{
						return -1;
					} // end else
				} // end if: encoding
				
				// Else decoding
				else
				{
					byte[] b4 = new byte[4];
					int i = 0;
					for (i = 0; i < 4; i++)
					{
						// Read four "meaningful" bytes:
						int b = 0;
						do
						{
							b = in.read();
						}
						while ((b >= 0)
							&& (Base64.DECODABET[b & 0x7f] <= Base64.WHITE_SPACE_ENC));
						
						if (b < 0)
						{
							break; // Reads a -1 if end of stream
						}
						
						b4[i] = (byte) b;
					} // end for: each needed input byte
					
					if (i == 4)
					{
						numSigBytes = Base64.decode4to3(b4,0,buffer,0);
						position = 0;
					} // end if: got four characters
					else if (i == 0)
					{
						return -1;
					} // end else if: also padded correctly
					else
					{
						// Must have broken out from above.
						throw new java.io.IOException(
							"Improperly padded Base64 input.");
					} // end
					
				} // end else: decode
			} // end else: get data
			
			// Got data?
			if (position >= 0)
			{
				// End of relevant data?
				if ( /* !encode && */position >= numSigBytes)
				{
					return -1;
				}
				
				if (encode && breakLines
					&& (lineLength >= Base64.MAX_LINE_LENGTH))
				{
					lineLength = 0;
					return '\n';
				} // end if
				else
				{
					lineLength++; // This isn't important when decoding
					// but throwing an extra "if" seems
					// just as wasteful.
					
					int b = buffer[position++];
					
					if (position >= bufferLength)
					{
						position = -1;
					}
					
					return b & 0xFF; // This is how you "cast" a byte that's
					// intended to be unsigned.
				} // end else
			} // end if: position >= 0
			
			// Else error
			else
			{
				// When JDK1.4 is more accepted, use an assertion here.
				throw new java.io.IOException(
					"Error in Base64 code reading stream.");
			} // end else
		} // end read
		
		/**
		 * Calls {@link #read} repeatedly until the end of stream
		 * is reached or <var>len</var> bytes are read.
		 * Returns number of bytes read into array or -1 if
		 * end of stream is encountered.
		 *
		 * @param dest array to hold values
		 * @param off offset for array
		 * @param len max number of bytes to read into array
		 * @return bytes read into array or -1 if end of stream is encountered.
		 * @since 1.3
		 */
		@Override
		public int read(byte[] dest,int off,int len)
			throws java.io.IOException
		{
			int i;
			int b;
			for (i = 0; i < len; i++)
			{
				b = read();
				
				// if( b < 0 && i == 0 )
				// return -1;
				
				if (b >= 0)
				{
					dest[off + i] = (byte) b;
				}
				else if (i == 0)
				{
					return -1;
				}
				else
				{
					break; // Out of 'for' loop
				}
			} // end for: each byte read
			return i;
		} // end read
		
	} // end inner class InputStream
	
	/**
	 * A {@link Base64#OutputStream} will write data to another
	 * {@link java.io.OutputStream}, given in the constructor,
	 * and encode/decode to/from Base64 notation on the fly.
	 *
	 * @see Base64
	 * @see java.io.FilterOutputStream
	 * @since 1.3
	 */
	public static class OutputStream
		extends java.io.FilterOutputStream
	{
		private boolean encode;
		private int position;
		private byte[] buffer;
		private int bufferLength;
		private int lineLength;
		private boolean breakLines;
		
		/**
		 * Constructs a {@link Base64#OutputStream} in ENCODE mode.
		 *
		 * @param out the {@link java.io.OutputStream} to which data will be written.
		 * @since 1.3
		 */
		public OutputStream(java.io.OutputStream out)
		{
			this(out,Base64.ENCODE);
		} // end constructor
		
		/**
		 * Constructs a {@link Base64#OutputStream} in
		 * either ENCODE or DECODE mode.
		 *
		 * @param out the {@link java.io.OutputStream} to which data will be written.
		 * @param encode Conversion direction
		 * @see Base64#ENCODE
		 * @see Base64#DECODE
		 * @since 1.3
		 */
		public OutputStream(java.io.OutputStream out,boolean encode)
		{
			this(out,encode,true);
		} // end constructor
		
		/**
		 * Constructs a {@link Base64#OutputStream} in
		 * either ENCODE or DECODE mode.
		 *
		 * @param out the {@link java.io.OutputStream} to which data will be written.
		 * @param encode Conversion direction
		 * @param breakLines Break lines to be less than 80 characters.
		 * @see Base64#ENCODE
		 * @see Base64#DECODE
		 * @since 1.3
		 */
		public OutputStream(java.io.OutputStream out,boolean encode,
			boolean breakLines)
		{
			super(out);
			this.breakLines = breakLines;
			this.encode = encode;
			bufferLength = encode
				? 3
				: 4;
			buffer = new byte[bufferLength];
			position = 0;
			lineLength = 0;
		} // end constructor
		
		/** 
		 * Flushes and closes (I think, in the superclass) the stream. 
		 *
		 * @since 1.3
		 */
		@Override
		public void close()
			throws java.io.IOException
		{
			super.close();
			// this.flush();
			
			out.close();
			
			buffer = null;
			out = null;
		} // end close
		
		/**
		 * Appropriately pads Base64 notation when encoding
		 * or throws an exception if Base64 input is not
		 * properly padded when decoding.
		 *
		 * @since 1.3
		 */
		@Override
		public void flush()
			throws java.io.IOException
		{
			super.flush();
			
			if (position > 0)
			{
				if (encode)
				{
					out.write(Base64.encode3to4(buffer,position));
					position = 0;
				} // end if: encoding
				else
				{
					throw new java.io.IOException(
						"Base64 input not properly padded.");
				} // end else: decoding
			} // end if: buffer partially full
			
			out.flush();
		} // end flush
		
		/**
		 * Calls {@link #write} repeatedly until <var>len</var> 
		 * bytes are written.
		 *
		 * @param theBytes array from which to read bytes
		 * @param off offset for array
		 * @param len max number of bytes to read into array
		 * @since 1.3
		 */
		@Override
		public void write(byte[] theBytes,int off,int len)
			throws java.io.IOException
		{
			for (int i = 0; i < len; i++)
			{
				write(theBytes[off + i]);
			} // end for: each byte written
			
		} // end write
		
		/**
		 * Writes the byte to the output stream after
		 * converting to/from Base64 notation.
		 * When encoding, bytes are buffered three
		 * at a time before the output stream actually
		 * gets a write() call.
		 * When decoding, bytes are buffered four
		 * at a time.
		 *
		 * @param theByte the byte to write
		 * @since 1.3
		 */
		@Override
		public void write(int theByte)
			throws java.io.IOException
		{
			if (encode)
			{
				buffer[position++] = (byte) theByte;
				if (position >= bufferLength) // Enough to encode.
				{
					out.write(Base64.encode3to4(buffer,bufferLength));
					
					lineLength += 4;
					if (breakLines && (lineLength >= Base64.MAX_LINE_LENGTH))
					{
						out.write(Base64.NEW_LINE);
						lineLength = 0;
					} // end if: end of line
					
					position = 0;
				} // end if: enough to output
			} // end if: encoding
			
			// Else, Decoding
			else
			{
				// Meaningful Base64 character?
				if (Base64.DECODABET[theByte & 0x7f] > Base64.WHITE_SPACE_ENC)
				{
					buffer[position++] = (byte) theByte;
					if (position >= bufferLength) // Enough to output.
					{
						out.write(Base64.decode4to3(buffer));
						position = 0;
					} // end if: enough to output
				} // end if: meaningful base64 character
				else if (Base64.DECODABET[theByte & 0x7f] != Base64.WHITE_SPACE_ENC)
				{
					throw new java.io.IOException(
						"Invalid character in Base64 data.");
				} // end else: not white space either
			} // end else: decoding
		} // end write
		
	} // end inner class OutputStream
	
	/** Specify encoding (value is <tt>true</tt>). */
	public final static boolean ENCODE = true;
	
	/** Specify decoding (value is <tt>false</tt>). */
	public final static boolean DECODE = false;
	
	/** Specify that data should be compressed (value is <tt>true</tt>). */
	public final static boolean COMPRESS = true;
	
	/** Specify that data should not be compressed (value is <tt>false</tt>). */
	public final static boolean DONT_COMPRESS = false;
	
	/** Maximum line length (76) of Base64 output. */
	private final static int MAX_LINE_LENGTH = 76;
	
	/** The equals sign (=) as a byte. */
	private final static byte EQUALS_SIGN = (byte) '=';
	
	/** The new line character (\n) as a byte. */
	private final static byte NEW_LINE = (byte) '\n';
	
	/** The 64 valid Base64 values. */
	private final static byte[] ALPHABET =
			{
				(byte) 'A',
				(byte) 'B',
				(byte) 'C',
				(byte) 'D',
				(byte) 'E',
				(byte) 'F',
				(byte) 'G',
				(byte) 'H',
				(byte) 'I',
				(byte) 'J',
				(byte) 'K',
				(byte) 'L',
				(byte) 'M',
				(byte) 'N',
				(byte) 'O',
				(byte) 'P',
				(byte) 'Q',
				(byte) 'R',
				(byte) 'S',
				(byte) 'T',
				(byte) 'U',
				(byte) 'V',
				(byte) 'W',
				(byte) 'X',
				(byte) 'Y',
				(byte) 'Z',
				(byte) 'a',
				(byte) 'b',
				(byte) 'c',
				(byte) 'd',
				(byte) 'e',
				(byte) 'f',
				(byte) 'g',
				(byte) 'h',
				(byte) 'i',
				(byte) 'j',
				(byte) 'k',
				(byte) 'l',
				(byte) 'm',
				(byte) 'n',
				(byte) 'o',
				(byte) 'p',
				(byte) 'q',
				(byte) 'r',
				(byte) 's',
				(byte) 't',
				(byte) 'u',
				(byte) 'v',
				(byte) 'w',
				(byte) 'x',
				(byte) 'y',
				(byte) 'z',
				(byte) '0',
				(byte) '1',
				(byte) '2',
				(byte) '3',
				(byte) '4',
				(byte) '5',
				(byte) '6',
				(byte) '7',
				(byte) '8',
				(byte) '9',
				(byte) '+',
				(byte) '/'
			};
	/** 
	 * Translates a Base64 value to either its 6-bit reconstruction value
	 * or a negative number indicating some other meaning.
	 **/
	private final static byte[] DECODABET =
		{
			-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 0 - 8
			-5,
			-5, // Whitespace: Tab and Linefeed
			-9,
			-9, // Decimal 11 - 12
			-5, // Whitespace: Carriage Return
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9, // Decimal 14 - 26
			-9,
			-9,
			-9,
			-9,
			-9, // Decimal 27 - 31
			-5, // Whitespace: Space
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9,
			-9, // Decimal 33 - 42
			62, // Plus sign at decimal 43
			-9,
			-9,
			-9, // Decimal 44 - 46
			63, // Slash at decimal 47
			52,
			53,
			54,
			55,
			56,
			57,
			58,
			59,
			60,
			61, // Numbers zero through nine
			-9,
			-9,
			-9, // Decimal 58 - 60
			-1, // Equals sign at decimal 61
			-9,
			-9,
			-9, // Decimal 62 - 64
			0,
			1,
			2,
			3,
			4,
			5,
			6,
			7,
			8,
			9,
			10,
			11,
			12,
			13, // Letters 'A' through 'N'
			14,
			15,
			16,
			17,
			18,
			19,
			20,
			21,
			22,
			23,
			24,
			25, // Letters 'O' through 'Z'
			-9,
			-9,
			-9,
			-9,
			-9,
			-9, // Decimal 91 - 96
			26,
			27,
			28,
			29,
			30,
			31,
			32,
			33,
			34,
			35,
			36,
			37,
			38, // Letters 'a' through 'm'
			39,
			40,
			41,
			42,
			43,
			44,
			45,
			46,
			47,
			48,
			49,
			50,
			51, // Letters 'n' through 'z'
			-9,
			-9,
			-9,
			-9
		// Decimal 123 - 126
		/*
		 * ,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 127 - 139
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 140 - 152
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 153 - 165
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 166 - 178
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 179 - 191
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 192 - 204
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 205 - 217
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 218 - 230
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9, // Decimal 231 - 243
		 * -9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9 // Decimal 244 - 255
		 */
		};
	private final static byte BAD_ENCODING = -9; // Indicates error in encoding
	
	private final static byte WHITE_SPACE_ENC = -5; // Indicates white space in
													// encoding
	
	/*  ******** E N C O D I N G M E T H O D S ******** */

	private final static byte EQUALS_SIGN_ENC = -1; // Indicates equals sign in
													// encoding
	
	/** Defeats instantiation. */
	private Base64()
	{
	}
	
	/**
	 * Decodes Base64 content in byte array format and returns
	 * the decoded byte array.
	 *
	 * @param source The Base64 encoded data
	 * @param off    The offset of where to begin decoding
	 * @param len    The length of characters to decode
	 * @return decoded data
	 * @since 1.3
	 */
	public static byte[] decode(byte[] source,int off,int len)
	{
		int len34 = len * 3 / 4;
		byte[] outBuff = new byte[len34]; // Upper limit on size of output
		int outBuffPosn = 0;
		
		byte[] b4 = new byte[4];
		int b4Posn = 0;
		byte sbiCrop = 0;
		byte sbiDecode = 0;
		for (int i = off,n = off + len; i < n; i++)
		{
			sbiCrop = (byte) (source[i] & 0x7f); // Only the low seven bits
			sbiDecode = Base64.DECODABET[sbiCrop];
			
			if (sbiDecode >= Base64.WHITE_SPACE_ENC) // White space, Equals sign
														// or better
			{
				if (sbiDecode >= Base64.EQUALS_SIGN_ENC)
				{
					b4[b4Posn++] = sbiCrop;
					if (b4Posn > 3)
					{
						outBuffPosn +=
							Base64.decode4to3(b4,0,outBuff,outBuffPosn);
						b4Posn = 0;
						
						// If that was the equals sign, break out of 'for' loop
						if (sbiCrop == Base64.EQUALS_SIGN)
						{
							break;
						}
					} // end if: quartet built
					
				} // end if: equals sign or better
				
			} // end if: white space, equals sign or better
			else
			{
				// System.err.println( "Bad Base64 input character at " + i +
				// ": " + source[i] + "(decimal)" );
				return null;
			} // end else:
		} // each input character
		
		byte[] out = new byte[outBuffPosn];
		System.arraycopy(outBuff,0,out,0,outBuffPosn);
		return out;
	} // end decode
	
	/**
	 * Decodes data from Base64 notation.
	 *
	 * @param s the string to decode
	 * @return the decoded data
	 * @since 1.4
	 */
	public static byte[] decode(String s)
	{
		byte[] bytes = s.getBytes();
		return Base64.decode(bytes,0,bytes.length);
	} // end decode
	
	/**
	 * Decodes the first four bytes of array <var>fourBytes</var>
	 * and returns an array up to three bytes long with the
	 * decoded values.
	 *
	 * @param fourBytes the array with Base64 content
	 * @return array with decoded values
	 * @since 1.3
	 */
	private static byte[] decode4to3(byte[] fourBytes)
	{
		byte[] outBuff1 = new byte[3];
		int count = Base64.decode4to3(fourBytes,0,outBuff1,0);
		byte[] outBuff2 = new byte[count];
		
		System.arraycopy(outBuff1,0,outBuff2,0,count);
		
		return outBuff2;
	}
	
	/**
	 * Decodes four bytes from array <var>source</var>
	 * and writes the resulting bytes (up to three of them)
	 * to <var>destination</var>.
	 * The source and destination arrays can be manipulated
	 * anywhere along their length by specifying 
	 * <var>srcOffset</var> and <var>destOffset</var>.
	 * This method does not check to make sure your arrays
	 * are large enough to accomodate <var>srcOffset</var> + 4 for
	 * the <var>source</var> array or <var>destOffset</var> + 3 for
	 * the <var>destination</var> array.
	 * This method returns the actual number of bytes that 
	 * were converted from the Base64 encoding.
	 * 
	 *
	 * @param source the array to convert
	 * @param srcOffset the index where conversion begins
	 * @param destination the array to hold the conversion
	 * @param destOffset the index where output will be put
	 * @return the number of decoded bytes converted
	 * @since 1.3
	 */
	private static int decode4to3(byte[] source,int srcOffset,
		byte[] destination,int destOffset)
	{
		// Example: Dk==
		if (source[srcOffset + 2] == Base64.EQUALS_SIGN)
		{
			// Two ways to do the same thing. Don't know which way I like best.
			// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
			// )
			// | ( ( DECODABET[ source[ srcOffset + 1] ] << 24 ) >>> 12 );
			int outBuff =
				((Base64.DECODABET[source[srcOffset]] & 0xFF) << 18)
					| ((Base64.DECODABET[source[srcOffset + 1]] & 0xFF) << 12);
			
			destination[destOffset] = (byte) (outBuff >>> 16);
			return 1;
		}
		
		// Example: DkL=
		else if (source[srcOffset + 3] == Base64.EQUALS_SIGN)
		{
			// Two ways to do the same thing. Don't know which way I like best.
			// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 ) >>> 6
			// )
			// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
			// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 );
			int outBuff =
				((Base64.DECODABET[source[srcOffset]] & 0xFF) << 18)
					| ((Base64.DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
					| ((Base64.DECODABET[source[srcOffset + 2]] & 0xFF) << 6);
			
			destination[destOffset] = (byte) (outBuff >>> 16);
			destination[destOffset + 1] = (byte) (outBuff >>> 8);
			return 2;
		}
		
		// Example: DkLE
		else
		{
			try
			{
				// Two ways to do the same thing. Don't know which way I like
				// best.
				// int outBuff = ( ( DECODABET[ source[ srcOffset ] ] << 24 )
				// >>> 6 )
				// | ( ( DECODABET[ source[ srcOffset + 1 ] ] << 24 ) >>> 12 )
				// | ( ( DECODABET[ source[ srcOffset + 2 ] ] << 24 ) >>> 18 )
				// | ( ( DECODABET[ source[ srcOffset + 3 ] ] << 24 ) >>> 24 );
				int outBuff =
					((Base64.DECODABET[source[srcOffset]] & 0xFF) << 18)
						| ((Base64.DECODABET[source[srcOffset + 1]] & 0xFF) << 12)
						| ((Base64.DECODABET[source[srcOffset + 2]] & 0xFF) << 6)
						| ((Base64.DECODABET[source[srcOffset + 3]] & 0xFF));
				
				destination[destOffset] = (byte) (outBuff >> 16);
				destination[destOffset + 1] = (byte) (outBuff >> 8);
				destination[destOffset + 2] = (byte) (outBuff);
				
				return 3;
			}
			catch (Exception e)
			{
				System.out.println("" + source[srcOffset] + ": "
					+ (Base64.DECODABET[source[srcOffset]]));
				System.out.println("" + source[srcOffset + 1] + ": "
					+ (Base64.DECODABET[source[srcOffset + 1]]));
				System.out.println("" + source[srcOffset + 2] + ": "
					+ (Base64.DECODABET[source[srcOffset + 2]]));
				System.out.println("" + source[srcOffset + 3] + ": "
					+ (Base64.DECODABET[source[srcOffset + 3]]));
				return -1;
			} // e nd catch
		}
	} // end decodeToBytes
	
	/**
	 * Simple helper method that Base64-decodes a file
	 * and returns the decoded data or <tt>null</tt>
	 * if there was an error.
	 *
	 * @param encfile The file to read
	 * @return The decoded file or <tt>null</tt> if there was an error.
	 * @since 1.4
	 */
	public static byte[] decodeFromFile(String encfile)
	{
		return Base64.readFile(encfile,Base64.DECODE);
	} // end encodeFromFile
	
	/**
	 * Simple helper method that Base64-decodes data to a file.
	 *
	 * @param encdata The data to write.
	 * @param file The file to read.
	 * @return Whether or not the write was a success.
	 * @since 1.4
	 */
	public static boolean decodeToFile(byte[] encdata,String file)
	{
		return Base64.writeFile(encdata,file,Base64.DECODE);
	} // end encodeFromFile
	
	/**
	 * Attempts to decode Base64 data and deserialize a Java
	 * Object within. Returns <tt>null if there was an error.
	 *
	 * @param encodedObject The Base64 data to decode
	 * @return The decoded and deserialized object
	 * @since 1.4
	 */
	public static Object decodeToObject(String encodedObject)
	{
		byte[] objBytes = Base64.decode(encodedObject);
		
		java.io.ByteArrayInputStream bais = null;
		java.io.ObjectInputStream ois = null;
		
		try
		{
			bais = new java.io.ByteArrayInputStream(objBytes);
			ois = new java.io.ObjectInputStream(bais);
			
			return ois.readObject();
		} // end try
		catch (java.io.IOException e)
		{
			e.printStackTrace();
			return null;
		} // end catch
		catch (java.lang.ClassNotFoundException e)
		{
			e.printStackTrace();
			return null;
		} // end catch
		finally
		{
			try
			{
				bais.close();
			}
			catch (Exception ignored)
			{
			}
			try
			{
				ois.close();
			}
			catch (Exception ignored)
			{
			}
		} // end finally
	} // end decodeObject
	
	/**
	 * Decodes data from Base64 notation and
	 * returns it as a string.
	 * Equivlaent to calling
	 * <code>new String( decode( s ) )</code>
	 *
	 * @param s the strind to decode
	 * @return The data as a string
	 * @since 1.4
	 */
	public static String decodeToString(String s)
	{
		return new String(Base64.decode(s));
	} // end decodeToString
	
	/**
	 * Encodes the first three bytes of array <var>threeBytes</var>
	 * and returns a four-byte array in Base64 notation.
	 *
	 * @param threeBytes the array to convert
	 * @return four byte array in Base64 notation.
	 * @since 1.3
	 */
	private static byte[] encode3to4(byte[] threeBytes)
	{
		return Base64.encode3to4(threeBytes,3);
	} // end encodeToBytes
	
	/**
	 * Encodes up to the first three bytes of array <var>threeBytes</var>
	 * and returns a four-byte array in Base64 notation.
	 * The actual number of significant bytes in your array is
	 * given by <var>numSigBytes</var>.
	 * The array <var>threeBytes</var> needs only be as big as
	 * <var>numSigBytes</var>.
	 *
	 * @param threeBytes the array to convert
	 * @param numSigBytes the number of significant bytes in your array
	 * @return four byte array in Base64 notation.
	 * @since 1.3
	 */
	private static byte[] encode3to4(byte[] threeBytes,int numSigBytes)
	{
		byte[] dest = new byte[4];
		Base64.encode3to4(threeBytes,0,numSigBytes,dest,0);
		return dest;
	}
	
	/**
	 * Encodes up to three bytes of the array <var>source</var>
	 * and writes the resulting four Base64 bytes to <var>destination</var>.
	 * The source and destination arrays can be manipulated
	 * anywhere along their length by specifying 
	 * <var>srcOffset</var> and <var>destOffset</var>.
	 * This method does not check to make sure your arrays
	 * are large enough to accomodate <var>srcOffset</var> + 3 for
	 * the <var>source</var> array or <var>destOffset</var> + 4 for
	 * the <var>destination</var> array.
	 * The actual number of significant bytes in your array is
	 * given by <var>numSigBytes</var>.
	 *
	 * @param source the array to convert
	 * @param srcOffset the index where conversion begins
	 * @param numSigBytes the number of significant bytes in your array
	 * @param destination the array to hold the conversion
	 * @param destOffset the index where output will be put
	 * @return the <var>destination</var> array
	 * @since 1.3
	 */
	private static byte[] encode3to4(byte[] source,int srcOffset,
		int numSigBytes,byte[] destination,int destOffset)
	{
		// 1 2 3
		// 01234567890123456789012345678901 Bit position
		// --------000000001111111122222222 Array position from threeBytes
		// --------| || || || | Six bit groups to index ALPHABET
		// >>18 >>12 >> 6 >> 0 Right shift necessary
		// 0x3f 0x3f 0x3f Additional AND
		
		// Create buffer with zero-padding if there are only one or two
		// significant bytes passed in the array.
		// We have to shift left 24 in order to flush out the 1's that appear
		// when Java treats a value as negative that is cast from a byte to an
		// int.
		int inBuff = (numSigBytes > 0
			? ((source[srcOffset] << 24) >>> 8)
			: 0) | (numSigBytes > 1
			? ((source[srcOffset + 1] << 24) >>> 16)
			: 0) | (numSigBytes > 2
			? ((source[srcOffset + 2] << 24) >>> 24)
			: 0);
		
		switch (numSigBytes)
		{
			case 3:
				destination[destOffset] = Base64.ALPHABET[(inBuff >>> 18)];
				destination[destOffset + 1] =
					Base64.ALPHABET[(inBuff >>> 12) & 0x3f];
				destination[destOffset + 2] =
					Base64.ALPHABET[(inBuff >>> 6) & 0x3f];
				destination[destOffset + 3] = Base64.ALPHABET[(inBuff) & 0x3f];
				return destination;
				
			case 2:
				destination[destOffset] = Base64.ALPHABET[(inBuff >>> 18)];
				destination[destOffset + 1] =
					Base64.ALPHABET[(inBuff >>> 12) & 0x3f];
				destination[destOffset + 2] =
					Base64.ALPHABET[(inBuff >>> 6) & 0x3f];
				destination[destOffset + 3] = Base64.EQUALS_SIGN;
				return destination;
				
			case 1:
				destination[destOffset] = Base64.ALPHABET[(inBuff >>> 18)];
				destination[destOffset + 1] =
					Base64.ALPHABET[(inBuff >>> 12) & 0x3f];
				destination[destOffset + 2] = Base64.EQUALS_SIGN;
				destination[destOffset + 3] = Base64.EQUALS_SIGN;
				return destination;
				
			default:
				return destination;
		} // end switch
	} // end encode3to4
	
	/**
	 * Encodes a byte array into Base64 notation.
	 * Equivalen to calling
	 * <code>encodeBytes( source, 0, source.length )</code>
	 *
	 * @param source The data to convert
	 * @since 1.4
	 */
	public static String encodeBytes(byte[] source)
	{
		return Base64.encodeBytes(source,true);
	} // end encodeBytes
	
	/**
	 * Encodes a byte array into Base64 notation.
	 * Equivalen to calling
	 * <code>encodeBytes( source, 0, source.length )</code>
	 *
	 * @param source The data to convert
	 * @param breakLines Break lines at 80 characters or less.
	 * @since 1.4
	 */
	public static String encodeBytes(byte[] source,boolean breakLines)
	{
		return Base64.encodeBytes(source,0,source.length,breakLines);
	} // end encodeBytes
	
	/**
	 * Encodes a byte array into Base64 notation.
	 *
	 * @param source The data to convert
	 * @param off Offset in array where conversion should begin
	 * @param len Length of data to convert
	 * @since 1.4
	 */
	public static String encodeBytes(byte[] source,int off,int len)
	{
		return Base64.encodeBytes(source,off,len,true);
	} // end encodeBytes
	
	/**
	 * Encodes a byte array into Base64 notation.
	 *
	 * @param source The data to convert
	 * @param off Offset in array where conversion should begin
	 * @param len Length of data to convert
	 * @param breakLines Break lines at 80 characters or less.
	 * @since 1.4
	 */
	public static String encodeBytes(byte[] source,int off,int len,
		boolean breakLines)
	{
		int len43 = len * 4 / 3;
		byte[] outBuff = new byte[(len43) // Main 4:3
			+ ((len % 3) > 0
				? 4
				: 0) // Account for padding
			+ (breakLines
				? (len43 / Base64.MAX_LINE_LENGTH)
				: 0)]; // New lines
		int d = 0;
		int e = 0;
		int len2 = len - 2;
		int lineLength = 0;
		for (; d < len2; d += 3,e += 4)
		{
			Base64.encode3to4(source,d + off,3,outBuff,e);
			
			lineLength += 4;
			if (breakLines && (lineLength == Base64.MAX_LINE_LENGTH))
			{
				outBuff[e + 4] = Base64.NEW_LINE;
				e++;
				lineLength = 0;
			} // end if: end of line
		} // en dfor: each piece of array
		
		if (d < len)
		{
			Base64.encode3to4(source,d + off,len - d,outBuff,e);
			e += 4;
		} // end if: some padding needed
		
		return new String(outBuff,0,e);
	} // end encodeBytes
	
	/**
	 * Simple helper method that Base64-encodes a file
	 * and returns the encoded string or <tt>null</tt>
	 * if there was an error.
	 *
	 * @param rawfile The file to read
	 * @return The encoded file or <tt>null</tt> if there was an error.
	 * @since 1.4
	 */
	public static String encodeFromFile(String rawfile)
	{
		byte[] ebytes = Base64.readFile(rawfile,Base64.ENCODE);
		
		return ebytes == null
			? null
			: new String(ebytes);
	} // end encodeFromFile
	
	/**
	 * Serializes an object and returns the Base64-encoded
	 * version of that serialized object. If the object
	 * cannot be serialized or there is another error,
	 * the method will return <tt>null</tt>.
	 *
	 * @param serializableObject The object to encode
	 * @return The Base64-encoded object
	 * @since 1.4
	 */
	public static String encodeObject(java.io.Serializable serializableObject)
	{
		return Base64.encodeObject(serializableObject,true);
	} // end encodeObject
	
	/**
	 * Serializes an object and returns the Base64-encoded
	 * version of that serialized object. If the object
	 * cannot be serialized or there is another error,
	 * the method will return <tt>null</tt>.
	 *
	 * @param serializableObject The object to encode
	 * @param breakLines Break lines at 80 characters or less.
	 * @return The Base64-encoded object
	 * @since 1.4
	 */
	public static String encodeObject(java.io.Serializable serializableObject,
		boolean breakLines)
	{
		java.io.ByteArrayOutputStream baos = null;
		java.io.OutputStream b64os = null;
		java.io.ObjectOutputStream oos = null;
		
		try
		{
			baos = new java.io.ByteArrayOutputStream();
			b64os = new Base64.OutputStream(baos,Base64.ENCODE,breakLines);
			oos = new java.io.ObjectOutputStream(b64os);
			
			oos.writeObject(serializableObject);
		} // end try
		catch (java.io.IOException e)
		{
			e.printStackTrace();
			return null;
		} // end catch
		finally
		{
			try
			{
				oos.close();
			}
			catch (Exception ignored)
			{
			}
			try
			{
				b64os.close();
			}
			catch (Exception ignored)
			{
			}
			try
			{
				baos.close();
			}
			catch (Exception ignored)
			{
			}
		} // end finally
		
		return new String(baos.toByteArray());
	} // end encode
	
	/*  ******** D E C O D I N G M E T H O D S ******** */

	/**
	 * Encodes a string in Base64 notation with line breaks
	 * after every 75 Base64 characters.
	 * Of course you probably only need to encode a string
	 * if there are non-ASCII characters in it such as many
	 * non-English languages.
	 *
	 * @param s the string to encode
	 * @return the encoded string
	 * @since 1.3
	 */
	public static String encodeString(String s)
	{
		return Base64.encodeString(s,true);
	} // end encodeString
	
	/**
	 * Encodes a string in Base64 notation with line breaks
	 * after every 75 Base64 characters.
	 * Of course you probably only need to encode a string
	 * if there are non-ASCII characters in it such as many
	 * non-English languages.
	 *
	 * @param s the string to encode
	 * @param breakLines Break lines at 80 characters or less.
	 * @return the encoded string
	 * @since 1.3
	 */
	public static String encodeString(String s,boolean breakLines)
	{
		return Base64.encodeBytes(s.getBytes(),breakLines);
	} // end encodeString
	
	/**
	 * Simple helper method that Base64-encodes data to a file.
	 *
	 * @param rawdata The data to write.
	 * @param file The file to read.
	 * @return Whether or not the write was a success.
	 * @since 1.4
	 */
	public static boolean encodeToFile(byte[] rawdata,String file)
	{
		return Base64.writeFile(rawdata,file,Base64.ENCODE);
	} // end encodeFromFile
	
	/**
	 * Reads a file and either encodes or decodes it.
	 *
	 * @param file The file to read
	 * @param encode Whether or not to encode file as it is read.
	 * @return The encoded/decoded file or <tt>null</tt> if there was an error.
	 * @since 1.4
	 */
	public static byte[] readFile(java.io.File file,boolean encode)
	{
		byte[] data = new byte[100];
		byte[] returnValue = null;
		int nextIndex = 0;
		int b = -1;
		Base64.InputStream bis = null;
		
		try
		{
			bis =
				new Base64.InputStream(new java.io.BufferedInputStream(
					new java.io.FileInputStream(file)),encode);
			
			while ((b = bis.read()) >= 0)
			{
				
				// Resize array?
				if (nextIndex >= data.length)
				{
					byte[] temp = new byte[data.length << 1];
					System.arraycopy(data,0,temp,0,data.length);
					data = temp;
				} // end if: resize array
				
				data[nextIndex++] = (byte) b;
				
			} // end while: each byte
			
			returnValue = new byte[nextIndex];
			System.arraycopy(data,0,returnValue,0,nextIndex);
			
		} // end try
		catch (java.io.IOException e)
		{
			returnValue = null;
		} // end catch
		finally
		{
			try
			{
				bis.close();
			}
			catch (Exception ignored)
			{
			}
		} // end finally
		
		return returnValue;
	} // end readFile
	
	/**
	 * Reads a file and either encodes or decodes it.
	 *
	 * @param file The file to read
	 * @param encode Whether or not to encode file as it is read.
	 * @return The encoded/decoded file or <tt>null</tt> if there was an error.
	 * @since 1.4
	 */
	public static byte[] readFile(String file,boolean encode)
	{
		return Base64.readFile(new java.io.File(file),encode);
	} // end readFile
	
	/**
	 * Writes a byte array to a file either encoding
	 * it or decoding it as specified.
	 *
	 * @param data The array to write to a file.
	 * @param offset The offset where the "real" data begins.
	 * @param length The amount of data to write.
	 * @param file The file to write to.
	 * @param encode Whether or not to encode the data.
	 * @return Whether or not the write was a success.
	 * @since 1.4
	 */
	public static boolean writeFile(byte[] data,int offset,int length,
		java.io.File file,boolean encode)
	{
		Base64.OutputStream bos = null;
		boolean success = false;
		
		try
		{
			bos =
				new Base64.OutputStream(new java.io.BufferedOutputStream(
					new java.io.FileOutputStream(file)),encode);
			
			bos.write(data,offset,length);
			success = true;
			
		} // end try
		catch (java.io.IOException e)
		{
			success = false;
		} // end catch
		finally
		{
			try
			{
				bos.close();
			}
			catch (Exception ignored)
			{
			}
		} // end finally
		
		return success;
	} // end writeFile
	
	/*  ******** I N N E R C L A S S I N P U T S T R E A M ******** */

	/**
	 * Writes a byte array to a file either encoding
	 * it or decoding it as specified.
	 *
	 * @param data The array to write to a file.
	 * @param file The file to write to.
	 * @param encode Whether or not to encode the data.
	 * @return Whether or not the write was a success.
	 * @since 1.4
	 */
	public static boolean writeFile(byte[] data,java.io.File file,boolean encode)
	{
		return Base64.writeFile(data,0,data.length,file,encode);
	} // end writeFile
	
	/*  ******** I N N E R C L A S S O U T P U T S T R E A M ******** */

	/**
	 * Writes a byte array to a file either encoding
	 * it or decoding it as specified.
	 *
	 * @param data The array to write to a file.
	 * @param file The file to write to.
	 * @param encode Whether or not to encode the data.
	 * @return Whether or not the write was a success.
	 * @since 1.4
	 */
	public static boolean writeFile(byte[] data,String file,boolean encode)
	{
		return Base64.writeFile(data,0,data.length,new java.io.File(file),
			encode);
	} // end writeFile
	
} // end class Base64
